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2022-10-12KVM: s390: Pass initialized arg even if unusedJanis Schoetterl-Glausch1-3/+13
[ Upstream commit b3cefd6bf16e7234ffbd4209f6083060f4e35f59 ] This silences smatch warnings reported by kbuild bot: arch/s390/kvm/gaccess.c:859 guest_range_to_gpas() error: uninitialized symbol 'prot'. arch/s390/kvm/gaccess.c:1064 access_guest_with_key() error: uninitialized symbol 'prot'. This is because it cannot tell that the value is not used in this case. The trans_exc* only examine prot if code is PGM_PROTECTION. Pass a dummy value for other codes. Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220825192540.1560559-1-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15s390/boot: fix absolute zero lowcore corruption on bootAlexander Gordeev2-1/+2
[ Upstream commit 12dd19c159659ec9050f45dc8a2ff3c3917f4be3 ] Crash dump always starts on CPU0. In case CPU0 is offline the prefix page is not installed and the absolute zero lowcore is used. However, struct lowcore::mcesad is never assigned and stays zero. That leads to __machine_kdump() -> save_vx_regs() call silently stores vector registers to the absolute lowcore at 0x11b0 offset. Fixes: a62bc0739253 ("s390/kdump: add support for vector extension") Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-08s390: fix nospec table alignmentsJosh Poimboeuf1-0/+1
commit c9305b6c1f52060377c72aebe3a701389e9f3172 upstream. Add proper alignment for .nospec_call_table and .nospec_return_table in vmlinux. [hca@linux.ibm.com]: The problem with the missing alignment of the nospec tables exist since a long time, however only since commit e6ed91fd0768 ("s390/alternatives: remove padding generation code") and with CONFIG_RELOCATABLE=n the kernel may also crash at boot time. The above named commit reduced the size of struct alt_instr by one byte, so its new size is 11 bytes. Therefore depending on the number of cpu alternatives the size of the __alt_instructions array maybe odd, which again also causes that the addresses of the nospec tables will be odd. If the address of __nospec_call_start is odd and the kernel is compiled With CONFIG_RELOCATABLE=n the compiler may generate code that loads the address of __nospec_call_start with a 'larl' instruction. This will generate incorrect code since the 'larl' instruction only works with even addresses. In result the members of the nospec tables will be accessed with an off-by-one offset, which subsequently may lead to addressing exceptions within __nospec_revert(). Fixes: f19fbd5ed642 ("s390: introduce execute-trampolines for branches") Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Link: https://lore.kernel.org/r/8719bf1ce4a72ebdeb575200290094e9ce047bcc.1661557333.git.jpoimboe@kernel.org Cc: <stable@vger.kernel.org> # 4.16 Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-08s390/hugetlb: fix prepare_hugepage_range() check for 2 GB hugepagesGerald Schaefer1-2/+4
commit 7c8d42fdf1a84b1a0dd60d6528309c8ec127e87c upstream. The alignment check in prepare_hugepage_range() is wrong for 2 GB hugepages, it only checks for 1 MB hugepage alignment. This can result in kernel crash in __unmap_hugepage_range() at the BUG_ON(start & ~huge_page_mask(h)) alignment check, for mappings created with MAP_FIXED at unaligned address. Fix this by correctly handling multiple hugepage sizes, similar to the generic version of prepare_hugepage_range(). Fixes: d08de8e2d867 ("s390/mm: add support for 2GB hugepages") Cc: <stable@vger.kernel.org> # 4.8+ Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-09-05s390/hypfs: avoid error message under KVMJuergen Gross2-2/+2
[ Upstream commit 7b6670b03641ac308aaa6fa2e6f964ac993b5ea3 ] When booting under KVM the following error messages are issued: hypfs.7f5705: The hardware system does not support hypfs hypfs.7a79f0: Initialization of hypfs failed with rc=-61 Demote the severity of first message from "error" to "info" and issue the second message only in other error cases. Signed-off-by: Juergen Gross <jgross@suse.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220620094534.18967-1-jgross@suse.com [arch/s390/hypfs/hypfs_diag.c changed description] Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-31s390: fix double free of GS and RI CBs on fork() failureBrian Foster1-6/+16
commit 13cccafe0edcd03bf1c841de8ab8a1c8e34f77d9 upstream. The pointers for guarded storage and runtime instrumentation control blocks are stored in the thread_struct of the associated task. These pointers are initially copied on fork() via arch_dup_task_struct() and then cleared via copy_thread() before fork() returns. If fork() happens to fail after the initial task dup and before copy_thread(), the newly allocated task and associated thread_struct memory are freed via free_task() -> arch_release_task_struct(). This results in a double free of the guarded storage and runtime info structs because the fields in the failed task still refer to memory associated with the source task. This problem can manifest as a BUG_ON() in set_freepointer() (with CONFIG_SLAB_FREELIST_HARDENED enabled) or KASAN splat (if enabled) when running trinity syscall fuzz tests on s390x. To avoid this problem, clear the associated pointer fields in arch_dup_task_struct() immediately after the new task is copied. Note that the RI flag is still cleared in copy_thread() because it resides in thread stack memory and that is where stack info is copied. Signed-off-by: Brian Foster <bfoster@redhat.com> Fixes: 8d9047f8b967c ("s390/runtime instrumentation: simplify task exit handling") Fixes: 7b83c6297d2fc ("s390/guarded storage: simplify task exit handling") Cc: <stable@vger.kernel.org> # 4.15 Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Link: https://lore.kernel.org/r/20220816155407.537372-1-bfoster@redhat.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-31s390/mm: do not trigger write fault when vma does not allow VM_WRITEGerald Schaefer1-1/+3
commit 41ac42f137080bc230b5882e3c88c392ab7f2d32 upstream. For non-protection pXd_none() page faults in do_dat_exception(), we call do_exception() with access == (VM_READ | VM_WRITE | VM_EXEC). In do_exception(), vma->vm_flags is checked against that before calling handle_mm_fault(). Since commit 92f842eac7ee3 ("[S390] store indication fault optimization"), we call handle_mm_fault() with FAULT_FLAG_WRITE, when recognizing that it was a write access. However, the vma flags check is still only checking against (VM_READ | VM_WRITE | VM_EXEC), and therefore also calling handle_mm_fault() with FAULT_FLAG_WRITE in cases where the vma does not allow VM_WRITE. Fix this by changing access check in do_exception() to VM_WRITE only, when recognizing write access. Link: https://lkml.kernel.org/r/20220811103435.188481-3-david@redhat.com Fixes: 92f842eac7ee3 ("[S390] store indication fault optimization") Cc: <stable@vger.kernel.org> Reported-by: David Hildenbrand <david@redhat.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-17Revert "s390/smp: enforce lowcore protection on CPU restart"Alexander Gordeev1-1/+1
commit 953503751a426413ea8aee2299ae3ee971b70d9b upstream. This reverts commit 6f5c672d17f583b081e283927f5040f726c54598. This breaks normal crash dump when CPU0 is offline. Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-08-17s390/unwind: fix fgraph return address recoverySumanth Korikkar1-1/+1
[ Upstream commit ded466e1806686794b403ebf031133bbaca76bb2 ] When HAVE_FUNCTION_GRAPH_RET_ADDR_PTR is defined, the return address to the fgraph caller is recovered by tagging it along with the stack pointer of ftrace stack. This makes the stack unwinding more reliable. When the fgraph return address is modified to return_to_handler, ftrace_graph_ret_addr tries to restore it to the original value using tagged stack pointer. Fix this by passing tagged sp to ftrace_graph_ret_addr. Fixes: d81675b60d09 ("s390/unwind: recover kretprobe modified return address in stacktrace") Cc: <stable@vger.kernel.org> # 5.18 Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17kexec, KEYS, s390: Make use of built-in and secondary keyring for signature ↵Michal Suchanek1-5/+13
verification [ Upstream commit 0828c4a39be57768b8788e8cbd0d84683ea757e5 ] commit e23a8020ce4e ("s390/kexec_file: Signature verification prototype") adds support for KEXEC_SIG verification with keys from platform keyring but the built-in keys and secondary keyring are not used. Add support for the built-in keys and secondary keyring as x86 does. Fixes: e23a8020ce4e ("s390/kexec_file: Signature verification prototype") Cc: stable@vger.kernel.org Cc: Philipp Rudo <prudo@linux.ibm.com> Cc: kexec@lists.infradead.org Cc: keyrings@vger.kernel.org Cc: linux-security-module@vger.kernel.org Signed-off-by: Michal Suchanek <msuchanek@suse.de> Reviewed-by: "Lee, Chun-Yi" <jlee@suse.com> Acked-by: Baoquan He <bhe@redhat.com> Signed-off-by: Coiby Xu <coxu@redhat.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17kexec_file: drop weak attribute from functionsNaveen N. Rao1-0/+3
[ Upstream commit 65d9a9a60fd71be964effb2e94747a6acb6e7015 ] As requested (http://lkml.kernel.org/r/87ee0q7b92.fsf@email.froward.int.ebiederm.org), this series converts weak functions in kexec to use the #ifdef approach. Quoting the 3e35142ef99fe ("kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]") changelog: : Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") : [1], binutils (v2.36+) started dropping section symbols that it thought : were unused. This isn't an issue in general, but with kexec_file.c, gcc : is placing kexec_arch_apply_relocations[_add] into a separate : .text.unlikely section and the section symbol ".text.unlikely" is being : dropped. Due to this, recordmcount is unable to find a non-weak symbol in : .text.unlikely to generate a relocation record against. This patch (of 2); Drop __weak attribute from functions in kexec_file.c: - arch_kexec_kernel_image_probe() - arch_kimage_file_post_load_cleanup() - arch_kexec_kernel_image_load() - arch_kexec_locate_mem_hole() - arch_kexec_kernel_verify_sig() arch_kexec_kernel_image_load() calls into kexec_image_load_default(), so drop the static attribute for the latter. arch_kexec_kernel_verify_sig() is not overridden by any architecture, so drop the __weak attribute. Link: https://lkml.kernel.org/r/cover.1656659357.git.naveen.n.rao@linux.vnet.ibm.com Link: https://lkml.kernel.org/r/2cd7ca1fe4d6bb6ca38e3283c717878388ed6788.1656659357.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Suggested-by: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17s390/smp: enforce lowcore protection on CPU restartAlexander Gordeev1-1/+1
[ Upstream commit 6f5c672d17f583b081e283927f5040f726c54598 ] As result of commit 915fea04f932 ("s390/smp: enable DAT before CPU restart callback is called") the low-address protection bit gets mistakenly unset in control register 0 save area of the absolute zero memory. That area is used when manual PSW restart happened to hit an offline CPU. In this case the low-address protection for that CPU will be dropped. Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Fixes: 915fea04f932 ("s390/smp: enable DAT before CPU restart callback is called") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17s390/crash: fix incorrect number of bytes to copy to user spaceAlexander Gordeev1-1/+1
[ Upstream commit f6749da17a34eb08c9665f072ce7c812ff68aad2 ] The number of bytes in a chunk is correctly calculated, but instead the total number of bytes is passed to copy_to_user_real() function. Reported-by: Matthew Wilcox <willy@infradead.org> Fixes: df9694c7975f ("s390/dump: streamline oldmem copy functions") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17virtio: replace restricted mem access flag with callbackJuergen Gross1-2/+2
[ Upstream commit a603002eea8213eec5211be5a85db8340aea06d0 ] Instead of having a global flag to require restricted memory access for all virtio devices, introduce a callback which can select that requirement on a per-device basis. For convenience add a common function returning always true, which can be used for use cases like SEV. Per default use a callback always returning false. As the callback needs to be set in early init code already, add a virtio anchor which is builtin in case virtio is enabled. Signed-off-by: Juergen Gross <jgross@suse.com> Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 guest using Xen Reviewed-by: Stefano Stabellini <sstabellini@kernel.org> Link: https://lore.kernel.org/r/20220622063838.8854-2-jgross@suse.com Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17KVM: s390: pv: leak the topmost page table when destroy failsClaudio Imbrenda3-3/+94
[ Upstream commit faa2f72cb3569256480c5540d242c84e99965160 ] Each secure guest must have a unique ASCE (address space control element); we must avoid that new guests use the same page for their ASCE, to avoid errors. Since the ASCE mostly consists of the address of the topmost page table (plus some flags), we must not return that memory to the pool unless the ASCE is no longer in use. Only a successful Destroy Secure Configuration UVC will make the ASCE reusable again. If the Destroy Configuration UVC fails, the ASCE cannot be reused for a secure guest (either for the ASCE or for other memory areas). To avoid a collision, it must not be used again. This is a permanent error and the page becomes in practice unusable, so we set it aside and leak it. On failure we already leak other memory that belongs to the ultravisor (i.e. the variable and base storage for a guest) and not leaking the topmost page table was an oversight. This error (and thus the leakage) should not happen unless the hardware is broken or KVM has some unknown serious bug. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Fixes: 29b40f105ec8d55 ("KVM: s390: protvirt: Add initial vm and cpu lifecycle handling") Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Link: https://lore.kernel.org/r/20220628135619.32410-2-imbrenda@linux.ibm.com Message-Id: <20220628135619.32410-2-imbrenda@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-08-17KVM: s390: pv: don't present the ecall interrupt twiceNico Boehr2-2/+17
commit c3f0e5fd2d33d80c5a5a8b5e5d2bab2841709cc8 upstream. When the SIGP interpretation facility is present and a VCPU sends an ecall to another VCPU in enabled wait, the sending VCPU receives a 56 intercept (partial execution), so KVM can wake up the receiving CPU. Note that the SIGP interpretation facility will take care of the interrupt delivery and KVM's only job is to wake the receiving VCPU. For PV, the sending VCPU will receive a 108 intercept (pv notify) and should continue like in the non-PV case, i.e. wake the receiving VCPU. For PV and non-PV guests the interrupt delivery will occur through the SIGP interpretation facility on SIE entry when SIE finds the X bit in the status field set. However, in handle_pv_notification(), there was no special handling for SIGP, which leads to interrupt injection being requested by KVM for the next SIE entry. This results in the interrupt being delivered twice: once by the SIGP interpretation facility and once by KVM through the IICTL. Add the necessary special handling in handle_pv_notification(), similar to handle_partial_execution(), which simply wakes the receiving VCPU and leave interrupt delivery to the SIGP interpretation facility. In contrast to external calls, emergency calls are not interpreted but also cause a 108 intercept, which is why we still need to call handle_instruction() for SIGP orders other than ecall. Since kvm_s390_handle_sigp_pei() is now called for all SIGP orders which cause a 108 intercept - even if they are actually handled by handle_instruction() - move the tracepoint in kvm_s390_handle_sigp_pei() to avoid possibly confusing trace messages. Signed-off-by: Nico Boehr <nrb@linux.ibm.com> Cc: <stable@vger.kernel.org> # 5.7 Fixes: da24a0cc58ed ("KVM: s390: protvirt: Instruction emulation") Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Link: https://lore.kernel.org/r/20220718130434.73302-1-nrb@linux.ibm.com Message-Id: <20220718130434.73302-1-nrb@linux.ibm.com> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-07-26Merge tag 's390-5.19-7' of ↵Linus Torvalds1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fix from Alexander GordeevL - Prevent relatively slow PRNO TRNG random number operation from being called from interrupt context. That could for example cause some network loads to timeout. * tag 's390-5.19-7' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/archrandom: prevent CPACF trng invocations in interrupt context
2022-07-21s390/archrandom: prevent CPACF trng invocations in interrupt contextHarald Freudenberger1-3/+6
This patch slightly reworks the s390 arch_get_random_seed_{int,long} implementation: Make sure the CPACF trng instruction is never called in any interrupt context. This is done by adding an additional condition in_task(). Justification: There are some constrains to satisfy for the invocation of the arch_get_random_seed_{int,long}() functions: - They should provide good random data during kernel initialization. - They should not be called in interrupt context as the TRNG instruction is relatively heavy weight and may for example make some network loads cause to timeout and buck. However, it was not clear what kind of interrupt context is exactly encountered during kernel init or network traffic eventually calling arch_get_random_seed_long(). After some days of investigations it is clear that the s390 start_kernel function is not running in any interrupt context and so the trng is called: Jul 11 18:33:39 t35lp54 kernel: [<00000001064e90ca>] arch_get_random_seed_long.part.0+0x32/0x70 Jul 11 18:33:39 t35lp54 kernel: [<000000010715f246>] random_init+0xf6/0x238 Jul 11 18:33:39 t35lp54 kernel: [<000000010712545c>] start_kernel+0x4a4/0x628 Jul 11 18:33:39 t35lp54 kernel: [<000000010590402a>] startup_continue+0x2a/0x40 The condition in_task() is true and the CPACF trng provides random data during kernel startup. The network traffic however, is more difficult. A typical call stack looks like this: Jul 06 17:37:07 t35lp54 kernel: [<000000008b5600fc>] extract_entropy.constprop.0+0x23c/0x240 Jul 06 17:37:07 t35lp54 kernel: [<000000008b560136>] crng_reseed+0x36/0xd8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b5604b8>] crng_make_state+0x78/0x340 Jul 06 17:37:07 t35lp54 kernel: [<000000008b5607e0>] _get_random_bytes+0x60/0xf8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b56108a>] get_random_u32+0xda/0x248 Jul 06 17:37:07 t35lp54 kernel: [<000000008aefe7a8>] kfence_guarded_alloc+0x48/0x4b8 Jul 06 17:37:07 t35lp54 kernel: [<000000008aeff35e>] __kfence_alloc+0x18e/0x1b8 Jul 06 17:37:07 t35lp54 kernel: [<000000008aef7f10>] __kmalloc_node_track_caller+0x368/0x4d8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b611eac>] kmalloc_reserve+0x44/0xa0 Jul 06 17:37:07 t35lp54 kernel: [<000000008b611f98>] __alloc_skb+0x90/0x178 Jul 06 17:37:07 t35lp54 kernel: [<000000008b6120dc>] __napi_alloc_skb+0x5c/0x118 Jul 06 17:37:07 t35lp54 kernel: [<000000008b8f06b4>] qeth_extract_skb+0x13c/0x680 Jul 06 17:37:07 t35lp54 kernel: [<000000008b8f6526>] qeth_poll+0x256/0x3f8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b63d76e>] __napi_poll.constprop.0+0x46/0x2f8 Jul 06 17:37:07 t35lp54 kernel: [<000000008b63dbec>] net_rx_action+0x1cc/0x408 Jul 06 17:37:07 t35lp54 kernel: [<000000008b937302>] __do_softirq+0x132/0x6b0 Jul 06 17:37:07 t35lp54 kernel: [<000000008abf46ce>] __irq_exit_rcu+0x13e/0x170 Jul 06 17:37:07 t35lp54 kernel: [<000000008abf531a>] irq_exit_rcu+0x22/0x50 Jul 06 17:37:07 t35lp54 kernel: [<000000008b922506>] do_io_irq+0xe6/0x198 Jul 06 17:37:07 t35lp54 kernel: [<000000008b935826>] io_int_handler+0xd6/0x110 Jul 06 17:37:07 t35lp54 kernel: [<000000008b9358a6>] psw_idle_exit+0x0/0xa Jul 06 17:37:07 t35lp54 kernel: ([<000000008ab9c59a>] arch_cpu_idle+0x52/0xe0) Jul 06 17:37:07 t35lp54 kernel: [<000000008b933cfe>] default_idle_call+0x6e/0xd0 Jul 06 17:37:07 t35lp54 kernel: [<000000008ac59f4e>] do_idle+0xf6/0x1b0 Jul 06 17:37:07 t35lp54 kernel: [<000000008ac5a28e>] cpu_startup_entry+0x36/0x40 Jul 06 17:37:07 t35lp54 kernel: [<000000008abb0d90>] smp_start_secondary+0x148/0x158 Jul 06 17:37:07 t35lp54 kernel: [<000000008b935b9e>] restart_int_handler+0x6e/0x90 which confirms that the call is in softirq context. So in_task() covers exactly the cases where we want to have CPACF trng called: not in nmi, not in hard irq, not in soft irq but in normal task context and during kernel init. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Jason A. Donenfeld <Jason@zx2c4.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Link: https://lore.kernel.org/r/20220713131721.257907-1-freude@linux.ibm.com Fixes: e4f74400308c ("s390/archrandom: simplify back to earlier design and initialize earlier") [agordeev@linux.ibm.com changed desc, added Fixes and Link, removed -stable] Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-21mmu_gather: Remove per arch tlb_{start,end}_vma()Peter Zijlstra2-3/+1
Scattered across the archs are 3 basic forms of tlb_{start,end}_vma(). Provide two new MMU_GATHER_knobs to enumerate them and remove the per arch tlb_{start,end}_vma() implementations. - MMU_GATHER_NO_FLUSH_CACHE indicates the arch has flush_cache_range() but does *NOT* want to call it for each VMA. - MMU_GATHER_MERGE_VMAS indicates the arch wants to merge the invalidate across multiple VMAs if possible. With these it is possible to capture the three forms: 1) empty stubs; select MMU_GATHER_NO_FLUSH_CACHE and MMU_GATHER_MERGE_VMAS 2) start: flush_cache_range(), end: empty; select MMU_GATHER_MERGE_VMAS 3) start: flush_cache_range(), end: flush_tlb_range(); default Obviously, if the architecture does not have flush_cache_range() then it also doesn't need to select MMU_GATHER_NO_FLUSH_CACHE. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Will Deacon <will@kernel.org> Cc: David Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-07-13s390/nospec: remove unneeded header includesVasily Gorbik2-3/+1
Commit 4efd417f298b ("s390: raise minimum supported machine generation to z10") removed the usage of alternatives and lowcore in expolines macros. Remove unneeded header includes as well. With that, expoline.S doesn't require asm-offsets.h and expoline_prepare target dependency could be removed. Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Link: https://lore.kernel.org/r/patch-2.thread-d13b6c.git-d13b6c96fb5f.your-ad-here.call-01656331067-ext-4899@work.hours Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-07-13s390/nospec: build expoline.o for modules_prepare targetVasily Gorbik4-2/+12
When CONFIG_EXPOLINE_EXTERN is used expoline thunks are generated from arch/s390/lib/expoline.S and postlinked into every module. This is also true for external modules. Add expoline.o build to the modules_prepare target. Fixes: 1d2ad084800e ("s390/nospec: add an option to use thunk-extern") Reported-by: Joe Lawrence <joe.lawrence@redhat.com> Tested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Tested-by: C. Erastus Toe <ctoe@redhat.com> Tested-by: Joe Lawrence <joe.lawrence@redhat.com> Link: https://lore.kernel.org/r/patch-1.thread-d13b6c.git-a2387a74dc49.your-ad-here.call-01656331067-ext-4899@work.hours Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-30s390/qdio: Fix spelling mistakeZhang Jiaming1-3/+3
Change 'defineable' to 'definable'. Change 'paramater' to 'parameter'. Signed-off-by: Zhang Jiaming <jiaming@nfschina.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Link: https://lore.kernel.org/r/20220623060543.12870-1-jiaming@nfschina.com Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-30s390/archrandom: simplify back to earlier design and initialize earlierJason A. Donenfeld3-224/+12
s390x appears to present two RNG interfaces: - a "TRNG" that gathers entropy using some hardware function; and - a "DRBG" that takes in a seed and expands it. Previously, the TRNG was wired up to arch_get_random_{long,int}(), but it was observed that this was being called really frequently, resulting in high overhead. So it was changed to be wired up to arch_get_random_ seed_{long,int}(), which was a reasonable decision. Later on, the DRBG was then wired up to arch_get_random_{long,int}(), with a complicated buffer filling thread, to control overhead and rate. Fortunately, none of the performance issues matter much now. The RNG always attempts to use arch_get_random_seed_{long,int}() first, which means a complicated implementation of arch_get_random_{long,int}() isn't really valuable or useful to have around. And it's only used when reseeding, which means it won't hit the high throughput complications that were faced before. So this commit returns to an earlier design of just calling the TRNG in arch_get_random_seed_{long,int}(), and returning false in arch_get_ random_{long,int}(). Part of what makes the simplification possible is that the RNG now seeds itself using the TRNG at bootup. But this only works if the TRNG is detected early in boot, before random_init() is called. So this commit also causes that check to happen in setup_arch(). Cc: stable@vger.kernel.org Cc: Harald Freudenberger <freude@linux.ibm.com> Cc: Ingo Franzki <ifranzki@linux.ibm.com> Cc: Juergen Christ <jchrist@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Link: https://lore.kernel.org/r/20220610222023.378448-1-Jason@zx2c4.com Reviewed-by: Harald Freudenberger <freude@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-30s390/purgatory: remove duplicated build rule of kexec-purgatory.oMasahiro Yamada1-2/+1
This is equivalent to the pattern rule in scripts/Makefile.build. Having the dependency on $(obj)/purgatory.ro is enough. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20220613170902.1775211-3-masahiroy@kernel.org Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-30s390/purgatory: hard-code obj-y in MakefileMasahiro Yamada1-1/+1
The purgatory/ directory is entirely guarded in arch/s390/Kbuild. CONFIG_ARCH_HAS_KEXEC_PURGATORY is bool type. $(CONFIG_ARCH_HAS_KEXEC_PURGATORY) is always 'y' when Kbuild visits this Makefile for building. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20220613170902.1775211-2-masahiroy@kernel.org Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-30s390: remove unneeded 'select BUILD_BIN2C'Masahiro Yamada1-1/+0
Since commit 4c0f032d4963 ("s390/purgatory: Omit use of bin2c"), s390 builds the purgatory without using bin2c. Remove 'select BUILD_BIN2C' to avoid the unneeded build of bin2c. Fixes: 4c0f032d4963 ("s390/purgatory: Omit use of bin2c") Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Link: https://lore.kernel.org/r/20220613170902.1775211-1-masahiroy@kernel.org Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-23s390/pai: Fix multiple concurrent event installationThomas Richter1-3/+12
Two different events such as pai_crypto/KM_AES_128/ and pai_crypto/KM_AES_192/ can be installed multiple times on the same CPU and the events are executed concurrently: # perf stat -e pai_crypto/KM_AES_128/ -C0 -a -- sleep 5 & # sleep 2 # perf stat -e pai_crypto/KM_AES_192/ -C0 -a -- true This results in the first event being installed two times with two seconds delay. The kernel does install the second event after the first event has been deleted and re-added, as can be seen in the traces: 13:48:47.600350 paicrypt_start event 0x1007 (event KM_AES_128) 13:48:49.599359 paicrypt_stop event 0x1007 (event KM_AES_128) 13:48:49.599198 paicrypt_start event 0x1007 13:48:49.599199 paicrypt_start event 0x1008 13:48:49.599921 paicrypt_event_destroy event 0x1008 13:48:52.601507 paicrypt_event_destroy event 0x1007 This is caused by functions event_sched_in() and event_sched_out() which call the PMU's add() and start() functions on schedule_in and the PMU's stop() and del() functions on schedule_out. This is correct for events attached to processes. The pai_crypto events are system-wide events and not attached to processes. Since the kernel common code can not be changed easily, fix this issue and do not reset the event count value to zero each time the event is added and started. Instead use a flag and zero the event count value only when called immediately after the event has been initialized. Therefore only the first invocation of the the event's add() function initializes the event count value to zero. The following invocations of the event's add() function leave the current event count value untouched. Fixes: 39d62336f5c1 ("s390/pai: add support for cryptography counters") Reported-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-23s390/pai: Prevent invalid event number for pai_crypto PMUThomas Richter1-2/+3
The pai_crypto PMU has to check the event number. It has to be in the supported range. This is not the case, the lower limit is not checked. Fix this and obey the lower limit. Fixes: 39d62336f5c1 ("s390/pai: add support for cryptography counters") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Suggested-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-23s390/cpumf: Handle events cycles and instructions identicalThomas Richter1-1/+21
Events CPU_CYCLES and INSTRUCTIONS can be submitted with two different perf_event attribute::type values: - PERF_TYPE_HARDWARE: when invoked via perf tool predefined events name cycles or cpu-cycles or instructions. - pmu->type: when invoked via perf tool event name cpu_cf/CPU_CYLCES/ or cpu_cf/INSTRUCTIONS/. This invocation also selects the PMU to which the event belongs. Handle both type of invocations identical for events CPU_CYLCES and INSTRUCTIONS. They address the same hardware. The result is different when event modifier exclude_kernel is also set. Invocation with event modifier for user space event counting fails. Output before: # perf stat -e cpum_cf/cpu_cycles/u -- true Performance counter stats for 'true': <not supported> cpum_cf/cpu_cycles/u 0.000761033 seconds time elapsed 0.000076000 seconds user 0.000725000 seconds sys # Output after: # perf stat -e cpum_cf/cpu_cycles/u -- true Performance counter stats for 'true': 349,613 cpum_cf/cpu_cycles/u 0.000844143 seconds time elapsed 0.000079000 seconds user 0.000800000 seconds sys # Fixes: 6a82e23f45fe ("s390/cpumf: Adjust registration of s390 PMU device drivers") Signed-off-by: Thomas Richter <tmricht@linux.ibm.com> Acked-by: Sumanth Korikkar <sumanthk@linux.ibm.com> [agordeev@linux.ibm.com corrected commit ID of Fixes commit] Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-23s390/crash: make copy_oldmem_page() return number of bytes copiedAlexander Gordeev1-3/+4
Callback copy_oldmem_page() returns either error code or zero. Instead, it should return the error code or number of bytes copied. Fixes: df9694c7975f ("s390/dump: streamline oldmem copy functions") Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-23s390/crash: add missing iterator advance in copy_oldmem_page()Alexander Gordeev1-0/+7
In case old memory was successfully copied the passed iterator should be advanced as well. Currently copy_oldmem_page() is always called with single-segment iterator. Should that ever change - copy_oldmem_user and copy_oldmem_kernel() functions would need a rework to deal with multi-segment iterators. Fixes: 5d8de293c224 ("vmcore: convert copy_oldmem_page() to take an iov_iter") Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Tested-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
2022-06-10Merge tag 'for-linus-5.19a-rc2-tag' of ↵Linus Torvalds2-11/+3
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: - a small cleanup removing "export" of an __init function - a small series adding a new infrastructure for platform flags - a series adding generic virtio support for Xen guests (frontend side) * tag 'for-linus-5.19a-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: unexport __init-annotated xen_xlate_map_ballooned_pages() arm/xen: Assign xen-grant DMA ops for xen-grant DMA devices xen/grant-dma-ops: Retrieve the ID of backend's domain for DT devices xen/grant-dma-iommu: Introduce stub IOMMU driver dt-bindings: Add xen,grant-dma IOMMU description for xen-grant DMA ops xen/virtio: Enable restricted memory access using Xen grant mappings xen/grant-dma-ops: Add option to restrict memory access under Xen xen/grants: support allocating consecutive grants arm/xen: Introduce xen_setup_dma_ops() virtio: replace arch_has_restricted_virtio_memory_access() kernel: add platform_has() infrastructure
2022-06-09gcc-12: disable '-Warray-bounds' universally for nowLinus Torvalds2-9/+2
In commit 8b202ee21839 ("s390: disable -Warray-bounds") the s390 people disabled the '-Warray-bounds' warning for gcc-12, because the new logic in gcc would cause warnings for their use of the S390_lowcore macro, which accesses absolute pointers. It turns out gcc-12 has many other issues in this area, so this takes that s390 warning disable logic, and turns it into a kernel build config entry instead. Part of the intent is that we can make this all much more targeted, and use this conflig flag to disable it in only particular configurations that cause problems, with the s390 case as an example: select GCC12_NO_ARRAY_BOUNDS and we could do that for other configuration cases that cause issues. Or we could possibly use the CONFIG_CC_NO_ARRAY_BOUNDS thing in a more targeted way, and disable the warning only for particular uses: again the s390 case as an example: KBUILD_CFLAGS_DECOMPRESSOR += $(if $(CONFIG_CC_NO_ARRAY_BOUNDS),-Wno-array-bounds) but this ends up just doing it globally in the top-level Makefile, since the current issues are spread fairly widely all over: KBUILD_CFLAGS-$(CONFIG_CC_NO_ARRAY_BOUNDS) += -Wno-array-bounds We'll try to limit this later, since the gcc-12 problems are rare enough that *much* of the kernel can be built with it without disabling this warning. Cc: Kees Cook <keescook@chromium.org> Cc: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-06-06virtio: replace arch_has_restricted_virtio_memory_access()Juergen Gross2-11/+3
Instead of using arch_has_restricted_virtio_memory_access() together with CONFIG_ARCH_HAS_RESTRICTED_VIRTIO_MEMORY_ACCESS, replace those with platform_has() and a new platform feature PLATFORM_VIRTIO_RESTRICTED_MEM_ACCESS. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Borislav Petkov <bp@suse.de>
2022-06-05Merge tag 'bitmap-for-5.19-rc1' of https://github.com/norov/linuxLinus Torvalds1-7/+3
Pull bitmap updates from Yury Norov: - bitmap: optimize bitmap_weight() usage, from me - lib/bitmap.c make bitmap_print_bitmask_to_buf parseable, from Mauro Carvalho Chehab - include/linux/find: Fix documentation, from Anna-Maria Behnsen - bitmap: fix conversion from/to fix-sized arrays, from me - bitmap: Fix return values to be unsigned, from Kees Cook It has been in linux-next for at least a week with no problems. * tag 'bitmap-for-5.19-rc1' of https://github.com/norov/linux: (31 commits) nodemask: Fix return values to be unsigned bitmap: Fix return values to be unsigned KVM: x86: hyper-v: replace bitmap_weight() with hweight64() KVM: x86: hyper-v: fix type of valid_bank_mask ia64: cleanup remove_siblinginfo() drm/amd/pm: use bitmap_{from,to}_arr32 where appropriate KVM: s390: replace bitmap_copy with bitmap_{from,to}_arr64 where appropriate lib/bitmap: add test for bitmap_{from,to}_arr64 lib: add bitmap_{from,to}_arr64 lib/bitmap: extend comment for bitmap_(from,to)_arr32() include/linux/find: Fix documentation lib/bitmap.c make bitmap_print_bitmask_to_buf parseable MAINTAINERS: add cpumask and nodemask files to BITMAP_API arch/x86: replace nodes_weight with nodes_empty where appropriate mm/vmstat: replace cpumask_weight with cpumask_empty where appropriate clocksource: replace cpumask_weight with cpumask_empty in clocksource.c genirq/affinity: replace cpumask_weight with cpumask_empty where appropriate irq: mips: replace cpumask_weight with cpumask_empty where appropriate drm/i915/pmu: replace cpumask_weight with cpumask_empty where appropriate arch/x86: replace cpumask_weight with cpumask_empty where appropriate ...
2022-06-04Merge tag 'kthread-cleanups-for-v5.19' of ↵Linus Torvalds1-5/+7
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull kthread updates from Eric Biederman: "This updates init and user mode helper tasks to be ordinary user mode tasks. Commit 40966e316f86 ("kthread: Ensure struct kthread is present for all kthreads") caused init and the user mode helper threads that call kernel_execve to have struct kthread allocated for them. This struct kthread going away during execve in turned made a use after free of struct kthread possible. Here, commit 343f4c49f243 ("kthread: Don't allocate kthread_struct for init and umh") is enough to fix the use after free and is simple enough to be backportable. The rest of the changes pass struct kernel_clone_args to clean things up and cause the code to make sense. In making init and the user mode helpers tasks purely user mode tasks I ran into two complications. The function task_tick_numa was detecting tasks without an mm by testing for the presence of PF_KTHREAD. The initramfs code in populate_initrd_image was using flush_delayed_fput to ensuere the closing of all it's file descriptors was complete, and flush_delayed_fput does not work in a userspace thread. I have looked and looked and more complications and in my code review I have not found any, and neither has anyone else with the code sitting in linux-next" * tag 'kthread-cleanups-for-v5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: sched: Update task_tick_numa to ignore tasks without an mm fork: Stop allowing kthreads to call execve fork: Explicitly set PF_KTHREAD init: Deal with the init process being a user mode process fork: Generalize PF_IO_WORKER handling fork: Explicity test for idle tasks in copy_thread fork: Pass struct kernel_clone_args into copy_thread kthread: Don't allocate kthread_struct for init and umh
2022-06-03Merge tag 's390-5.19-2' of ↵Linus Torvalds18-211/+288
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull more s390 updates from Heiko Carstens: "Just a couple of small improvements, bug fixes and cleanups: - Add Eric Farman as maintainer for s390 virtio drivers. - Improve machine check handling, and avoid incorrectly injecting a machine check into a kvm guest. - Add cond_resched() call to gmap page table walker in order to avoid possible huge latencies. Also use non-quiesing sske instruction to speed up storage key handling. - Add __GFP_NORETRY to KEXEC_CONTROL_MEMORY_GFP so s390 behaves similar like common code. - Get sie control block address from correct stack slot in perf event code. This fixes potential random memory accesses. - Change uaccess code so that the exception handler sets the result of get_user() and __get_kernel_nofault() to zero in case of a fault. Until now this was done via input parameters for inline assemblies. Doing it via fault handling is what most or even all other architectures are doing. - Couple of other small cleanups and fixes" * tag 's390-5.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/stack: add union to reflect kvm stack slot usages s390/stack: merge empty stack frame slots s390/uaccess: whitespace cleanup s390/uaccess: use __noreturn instead of __attribute__((noreturn)) s390/uaccess: use exception handler to zero result on get_user() failure s390/uaccess: use symbolic names for inline assembler operands s390/mcck: isolate SIE instruction when setting CIF_MCCK_GUEST flag s390/mm: use non-quiescing sske for KVM switch to keyed guest s390/gmap: voluntarily schedule during key setting MAINTAINERS: Update s390 virtio-ccw s390/kexec: add __GFP_NORETRY to KEXEC_CONTROL_MEMORY_GFP s390/Kconfig.debug: fix indentation s390/Kconfig: fix indentation s390/perf: obtain sie_block from the right address s390: generate register offsets into pt_regs automatically s390: simplify early program check handler s390/crypto: fix scatterwalk_unmap() callers in AES-GCM
2022-06-03KVM: s390: replace bitmap_copy with bitmap_{from,to}_arr64 where appropriateYury Norov1-7/+3
Copying bitmaps from/to 64-bit arrays with bitmap_copy is not safe on 32-bit BE machines. Use designated functions instead. CC: Alexander Gordeev <agordeev@linux.ibm.com> CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com> CC: Christian Borntraeger <borntraeger@linux.ibm.com> CC: Claudio Imbrenda <imbrenda@linux.ibm.com> CC: David Hildenbrand <david@redhat.com> CC: Heiko Carstens <hca@linux.ibm.com> CC: Janosch Frank <frankja@linux.ibm.com> CC: Rasmus Villemoes <linux@rasmusvillemoes.dk> CC: Sven Schnelle <svens@linux.ibm.com> CC: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2022-06-02Merge tag 'livepatching-for-5.19' of ↵Linus Torvalds1-22/+0
git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching Pull livepatching cleanup from Petr Mladek: - Remove duplicated livepatch code [Christophe] * tag 'livepatching-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: livepatch: Remove klp_arch_set_pc() and asm/livepatch.h
2022-06-01s390/stack: add union to reflect kvm stack slot usagesHeiko Carstens3-6/+14
Add a union which describes how the empty stack slots are being used by kvm and perf. This should help to avoid another bug like the one which was fixed with commit c9bfb460c3e4 ("s390/perf: obtain sie_block from the right address"). Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Tested-by: Nico Boehr <nrb@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/stack: merge empty stack frame slotsHeiko Carstens3-8/+7
Merge empty1 and empty2 arrays within the stack frame to one single array. This is possible since with commit 42b01a553a56 ("s390: always use the packed stack layout") the alternative stack frame layout is gone. Reviewed-by: Nico Boehr <nrb@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/uaccess: whitespace cleanupHeiko Carstens1-66/+66
Whitespace cleanup to get rid if some checkpatch findings, but mainly to have consistent coding style within the header file again. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/uaccess: use __noreturn instead of __attribute__((noreturn))Heiko Carstens1-3/+4
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/uaccess: use exception handler to zero result on get_user() failureHeiko Carstens3-59/+143
Historically the uaccess code pre-initializes the result of get_user() (and now also __get_kernel_nofault()) to zero and uses the result as input parameter for inline assemblies. This is different to what most, if not all, other architectures are doing, which set the result to zero within the exception handler in case of a fault. Use the new extable mechanism and handle zeroing of the result within the exception handler in case of a fault. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/uaccess: use symbolic names for inline assembler operandsHeiko Carstens1-8/+8
Make code easier to read by using symbolic names. Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/mcck: isolate SIE instruction when setting CIF_MCCK_GUEST flagAlexander Gordeev1-1/+5
Commit d768bd892fc8 ("s390: add options to change branch prediction behaviour for the kernel") introduced .Lsie_exit label - supposedly to fence off SIE instruction. However, the corresponding address range length .Lsie_crit_mcck_length was not updated, which led to BPON code potentionally marked with CIF_MCCK_GUEST flag. Both .Lsie_exit and .Lsie_crit_mcck_length were removed with commit 0b0ed657fe00 ("s390: remove critical section cleanup from entry.S"), but the issue persisted - currently BPOFF and BPENTER macros might get wrongly considered by the machine check handler as a guest. Fixes: d768bd892fc8 ("s390: add options to change branch prediction behaviour for the kernel") Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/mm: use non-quiescing sske for KVM switch to keyed guestChristian Borntraeger1-1/+1
The switch to a keyed guest does not require a classic sske as the other guest CPUs are not accessing the key before the switch is complete. By using the NQ SSKE things are faster especially with multiple guests. Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Suggested-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220530092706.11637-3-borntraeger@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/gmap: voluntarily schedule during key settingChristian Borntraeger1-0/+14
With large and many guest with storage keys it is possible to create large latencies or stalls during initial key setting: rcu: INFO: rcu_sched self-detected stall on CPU rcu: 18-....: (2099 ticks this GP) idle=54e/1/0x4000000000000002 softirq=35598716/35598716 fqs=998 (t=2100 jiffies g=155867385 q=20879) Task dump for CPU 18: CPU 1/KVM R running task 0 1030947 256019 0x06000004 Call Trace: sched_show_task rcu_dump_cpu_stacks rcu_sched_clock_irq update_process_times tick_sched_handle tick_sched_timer __hrtimer_run_queues hrtimer_interrupt do_IRQ ext_int_handler ptep_zap_key The mmap lock is held during the page walking but since this is a semaphore scheduling is still possible. Same for the kvm srcu. To minimize overhead do this on every segment table entry or large page. Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220530092706.11637-2-borntraeger@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/kexec: add __GFP_NORETRY to KEXEC_CONTROL_MEMORY_GFPHeiko Carstens1-1/+1
Avoid invoking the OOM-killer when allocating the control page. This is the s390 variant of commit dc5cccacf427 ("kexec: don't invoke OOM-killer for control page allocation"). Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2022-06-01s390/Kconfig.debug: fix indentationJuerg Haefliger1-6/+6
The convention for indentation seems to be a single tab. Help text is further indented by an additional two whitespaces. Fix the lines that violate these rules. Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com> Link: https://lore.kernel.org/r/20220525120151.39594-1-juerg.haefliger@canonical.com Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-18 12:32:11 +0300